Tube coupling having a longitudinally movable biting ring



A. GOLDSTEIN May 3, 1966 TUBE COUPLING HAVING A LONGITUDINALLY MOVABLEBITING RING Filed Nov. 14, 1963 Flal llf//f/ vFIGB United States vPatentO 3,249,373 TUBE COUPLING HAVING A LONGITUDINALLY v MGVABLE BITING RINGArthur Goldstein, Richmond Heights, Mo., asslguor of one-half to GeorgeP. Goldstein and one-half to Kenneth Goldstein, both of St. LouisCounty, Mo.

Filed Nov. 14, 1963, Ser. No. 323,777

1 Claim. (Cl. 285-382) This invention relates generally to couplingdevices, but more especially to those that are intended to interlock apair of nestable tubes, pipes, conduits and the like against accidentalseparation.

The invention has among its general objects, the construction of such adevice that is simple and inexpensive in construction, extremely sturdyin service, easy and rapid to use, made of a single piece of material,and which will give good and satisfactory service wherever the need forits use arises.

Another object of mty invention is to so construct a device of the kindaforementioned, that after once positioned in interlocking position,will be very diiiicult, if not impossible, to separate the tubes withoutactually vdestroying the tubes themselves.

Many other objects and advantages of the construction herein shown anddescribed, and the uses thereof, will be obvious to those skilled in theart to which this invention appertains, as will be clearly evident fromthe specilication and claims that follow.

In the drawings, wherein like reference characters represent like orcorresponding parts throughout the views.

'FIGURE l is a longitudinalsectional view through a pair of tubes thatare about to be coupled together;

FIGURE 2 is al perspective view of the coupling devlce;

FIGURE 3 is a longitudinal sectional view of the cooperating pair oftubes, at about the initial and iinal assembly positions; and

FIGURE 4 is a detail sectional view, showing the teeth of the couplingdevice penetrating one of the tubes to interlock the tubes.

Referring more particularly to the drawings, wherein I have illustratedthe preferred embodiment of my invention, 1 and 2 indicates two lengthsof tubing of any preferred material, as for example of strongpaperboard, the first tube being suiciently larger in internal diameterthan the latter to permit of easy telescopic entry of the A latter intothe first tube, with plenty of lateral clearance therebetween.

A pair of annular bands 3 and 4, of suitable thickness,

are glued or otherwise suitably aiixed to the interior of the largertubeand arranged in axially spaced-apart relation therein, somewhat asshown, the former band being adjacent one end of the tube, land theother band placed a suitable distance inwardly of the tube therefrom.

Thesebands serve -as abutment stops for the coupling device, as will behereinafter explained, said device being longitudinally slidably movablein said tube between said bands.

The device may consist of a relatively thin one-piece ring having anydesired width, and preferably made of strong sheet metal, treated forproper hardness and flexibility as desired, to make it serve for the useto which it is to be put, the annular bounding portion of the ring beingindicated at 5.

One peripheral edge portion of said ring is bent reentrantly rearwardlyupon itself, into the ring, to provide a double-thicknessl portion 6 ofany appreciable width, `to thereby reinforce the ring thereabout.

There are teeth or prongs 7 formed to extend rearwardly from saidthickened portion of the edge, and arice ranged circumferentially, saidteeth extending toward the other edge of the ringand bent to extend atan angle to project radially inwardly of the annulus, somewhat asindicated, the external diameter of said ring being such that itvmayslidably move without interference within the larger tube, between saidbands until the ring abuts one or the other of the bands, depending onthe direction of its longitudinal travel.

The external outside diameter of the smaller tube is such that it willenter the larger tube, substantially initially slidably engaging thebands, the latter serving to center and guide the entering tube.

To assemble the tubes into coupled relationship, one

end of the smaller tube is inserted longitudinally into an adjacent endof the larger one and is longitudinally or axially advanced thereintountil said advancing or forward end of the tube engages the ring member.Continued advancement of the smaller tube actuates the coupling devicealong therewith, as indicated in dotted lines in FIG. 3, such advancingmovement continuing until the ring abuts the innermost band 4 to ceasefurther entering movement of the ring.

Now, continued advancement of the tube 2 rides the same along the teethof the ring to'flex them against the inner peripheral bounding surfaceof the ring to substantially flatten them, as indicated in full lines inFIG.v 3.

' The adjacent end of the smaller tube may be still further advancedpast the ring and project axially therebeyond the latter, as indicatedin full lines in FIG. 3.

-Now, any withdrawal movement of the tubes to separate them, as byshifting the smaller tube (to the right) relatively of the larger tube,from its position indicated in full lines in FIG. 3, will carry the ringwith the moving tube until the ring abuts the end band 3, which stopsfurther retraction of the ring, to thereby bend the teeth into the tubeand substantially gouge into the peripheral surface of the latter asindicated at 8 in FIG 4, any further withdrawal movement of the smallertube causing even deeper penetration of the teeth into the tube withfurther angular deiiection of the teeth, and the ilakedoff tube materialbuilding up between the teeth and the internal peripheral surface of thering to even more firmly wedge the teeth into the material of thesmaller tube to lock the tubes together thereabout.

The aforesaid interlock can be made very strong, as desired, and infact, tests have shown that a pull of approximately 800 pounds Could beexerted on an approximately 21/2 O D. paperboard tube, without breakingthe teeth.

What is claimed is:

In a device adapted for longitudinally coupling a pair of tubes one ofwhich is of smaller diameter than the other, a larger diameter tubehaving a pair of longitudinally spaced-apart annular bands fixedperipherally therein to serve as an abutment stop for said device, aring slidably seatable in said larger tube and adapted to abut one ofsaid bandsv `as its limit of longitudinal movement in one direction,said ring having a cylindrical portion whose diameter is substantiallyequal to the internal diameter of said larger tube and is bentreentrantly about one edge to form a double thickness of ring materialthereabout and of appreciable width, the innermost portion of saidreentrant material provided with teeth arranged circumferentiallythereabout and with their points directed inwardly from said edge andtoward the'center of the ring, the space between said bands beingsubstantially greater than the axial length of said ring, the internaldiameter of the bands being substantially that of the external diameterof the small tube, .and with the teeth points terminating radiallyinwardly beyond the internal surface of said bands, whereby withdrawalforce on said smaller tube causes increasing penetration of the teethinto the latter and a wedging of material scraped from the smaller tubeinto between the teeth vand the inner opposed peripl1 eral surface ofsaid ring.

References Cited by the Examiner UNITED STATES PATENTS l@ 5/1958Leadbetter ,285--382 X 8/1960 Kocsuta 285--340 9/1964 Briegel et al.285--322 X FOREIGN PATENTS 3/ 1960 Australia. 12/1951 Switzerland.

CARL W. 4TOMLIN, Primary Examiner.

22,5 340 10 THOMAS F. CALLAGHAN, Examiner.

